Uniden BC898T manual Understanding Scanning, Understanding Banks and Channels, What is Scanning?

Understanding Scanning

This section provides you with background on how scanning works. You don’t really need to know all of this to use your scanner, but some background knowledge will help you get the most from your BC898T.

Understanding Banks and Channels

The memory in your scanner is organized into 10 banks of 50 channels each. Each bank can contain conventional channels as well as 1 trunking system. For each trunking system, each bank can also store 10 groups of 10 talk group ID’s (100 per bank).

What is Scanning?

Unlike standard AM or FM radio stations, most two-way communications do not transmit continuously. Your BC898T scans programmed channels until it finds an active frequency, then stops on that frequency and remains on that channel as long as the transmission continues. When the transmission ends, the scanning cycle resumes until the scanner receives another transmission.

What is Searching?

The BC898T can search each of its 17 bands and up to ten bands together to find active frequencies. This is different from scanning because you are searching for frequencies that have not been programmed into the scanner. When you select frequency bands to search, the scanner searches for any active frequency within the lower and upper limits you specify. When the scanner finds an active frequency, it stops on that frequency as long as the transmission lasts. If you think the frequency is interesting, you can program it into one of the banks. If not, you can continue to search.

What is CTCSS/DCS?

Your scanner can monitor systems using a Continuous Tone Control Squelch (CTCSS) and Digital Coded Squelch (DCS) system, which allow squelch to open only when the tone you have programmed with a specific frequency is received along with a transmission.

CTCSS and DCS are subaudible tone signaling systems sometimes referred to as PL (Motorola’s trademarked term for Private Line). CTCSS and DCS are used only for FM signals and are usually associated with both amateur and commercial two-way repeaters. These systems make use of a special subaudible tone that accompanies a transmitted signal.

CTCSS and DCS are used for many purposes. In many cases, CTCSS and DCS are used to restrict access to a commercial repeater, so that only those units, which transmit the correct tone along with their signal can “talk to the repeater.”

CTCSS and DCS are also used in areas that receive interference where there are several stations with output frequencies close to each other. When this occurs, you might hear multiple communications at the same time. The stations might even interfere with each

7